Injection device



Aug. 5, 1952 J, SMOOT 2,605,763

INJECTION DEVICE Filed Jan. 31, 1948 3 Sheets-Sheet 1 lllllll ll J8 INVENTOR. 10/111 ,IY Smao/ BY M M Aug. 5, 1952 Filed Jan. 51, 1948 l I I I I II IH J. H. sMooT 2,605,763

INJECTION DEVICE s Shets-Sheet 2 70 I )j a FF INVENTOR.

g BYMMM HTTUIP EY Aug. 5, 1952 J. SMQOT 2,605,763

INJECTION DEVICE Filed Jan. 31, 1948 3 Sheets-Sheet 5 F zz/1 IN V EN TOR.

Jqkn 1y jmoof M M i/w Patented Aug. 5, 1952 UNITED STATES PATENT OFFICE,

John H. smoot, Da'rien, Conn-., 'assignor to Benton Dickinson and. Company, Rutherford, 'N. J a

corporation of New Jersey Application January 31, 1948, Serial N0. 5,540

'14 Claims. (Cl. BB 173) This invention relates to a structurally. -i-n'1.'-

, proved injection device and especially a'u'nit by means of which medicament may be hypodermically injected through the skin into theunderly- 'ing tissueswithout the aid ofa skin-penetrating needle.

-It is'an object of the invention to furnish a mechanism by means'of which-=without reload= ing -asuc'cessive series of "injections maybe made; each such injection presenting according to the discretionof the physician or operator a desired volume of medicament. I

Thus; a single injection maybe made Where a number 'ofsuccessive injections have heretofore been necessary to distribute into the tissue *a desired "dosage. "Also, the volume of these single injections'may be increased at will by constructmechanisms embodying the teachings of the present invention.

A further, object is'that er furnishing an apparatus in which the medicament during "dis charge -will be maintained under; substantially constant and even pressure and'will accordingly flow with constant velocity. "Therefore, the physician or other operator'may be assured that substantially the en'ti're predetermined medicament dosage hasb eenso injected rather than having a'portion of the dosage dispersed over the surfac'e'of the skin. r Y

"Still another object is that of furnishingan apparatus of this type which will be li'g ht'in weight, compact and portable and readily capable of" manipulation "by the operator. Additionally, when it becomes necessary to recharge-or refill the unit, this maybe donewith minimum-'efiort and in a short'interval z'of'time.

With these and other objects -in mind, r fer-- ence is had to the attached sheets of drewvin'gs illustrating practical embodiments of the invemti'on andin which: p

1 is aside elevation of'one form of-in"- je c tor';

Fig. 2 'is 'a longitudinal section of the same; Figs. 3 and 4 are transversesectional views taken respectively along the, lilie's"3 3 and-'4? and in the direction of the arrows as indicated inFig.-2; v H

5 is'fa fragmentary sectional side view of a portion of a uni showing analternative'form of s't'ructure; v 4 V p Fig. 6is a transverse sectional view taken along the l est s and"inthe-directionof the arrows as'indicate'din Fig. 5 I

' Fig. 7 is aview similar to still further-form of unit igi 'l'but showing-"a Fig. 8' is a sectional side view of the apparatus as shown in Fig. 7 I

Fig. 9-is' a transverse sectional View taken along the lines 9--9 and in the direction of the arrows as indicated in Fig.8;

Fig[ 10 is a side elevation of one of the inner members of the apparatus as shown in Fig. 8;

Fig. 11 is anemarged fragmentary and sectio'nal view through that portion of the unit containing'the valve mechanism; and

Fig. 1'2'is-a sectional view taken-along the lines 4 2 2- and in the direction of the arrows as indicated inFig. 11-.

It-is proposed according to the preferred embodi'ments of the invention to employ a compressed gas 1 as amotive force. That gas may different motive -force than gas under pressure might be utilized. Therefore, except where otherwise indicated in the appended claims, this feature of the present inventionis to be taken in an illustrative rather than in a limiting sense.

"Thus, in these views, the numeral l5 indicates a 'bjody which mounts acap member 16. Disposed within the latter is a flask I! of more or less conventionalconstruction and which has [an initially sealed neck portion 18 capable of being perforated-by a cannula l9 to afford access to the interior-of the flask. Adjacentits upper end the body "is 'formed with a threaded flange for mounting the cap it. The latter having screw threads 28 cooperating with corresponding threads iorminga part of body 15, it becomes feasible by "tightening the cap to press the flask I7 inwardly. 7 Such pr'ess'ure'obviously causes the pointed end ofc'annula I9 -to penetrate the sealing material lflin the neck of the flask. When the cannula has' 'once cleared this sealing material, then the gas under pressure may flowv through the bore of the cannula to other portions of the apparatus. 7 v v Commnn'i'catingwiththe bore of cannula i9 is p'assa gefll. 'This passage continues in the form" of' a passage122communicating with the upper end ofa cylinder 23 formedfin'the body 15. Within this cylinder, a piston 24 may be disposed. stem or rod 25 is afixed to or forms a part of the-piston and extends within -themain bore 26 of body [5.

interposed betweenpassages 2| and 22-is a valvemechanism. This mechanism may take one of several different forms. However, in additionto controlling the flow of gas under pressure from the flask I! or other source to the cylinder, the

which is contemplated as a part of the present 1 device in addition to including a readily controlled structure permitting of gas flow and inter ruption of gas flow, should also contemplate a.) .15;

I-gasunder pressure flowing from flask H or other structure such that pressures within the cylinder should be capable of being relieved. Having in mind that the ordinary physician or technician may not be especially adept in mechanical manipulation, such relief should occur substantially automatically.

. Thus, as especially shown in Figs. 11 and 12, transverse passages 2! and 28 may be, formed in the body l0 and connected with passages 2| and 22. These transverse passages may be connected by an axially extending passage portion 29. Within passage 27, a spring-pressed valve 30 may be disposed. From this valve an actuator 3| may extend through and beyond the exterior faceof body Ill. A packing assembly 32 may prevent a substantial escape of gas past the face of the actuator or stem 31. Likewise, the rear end of passage 2! maybe closed asindicated at 33 to prevent any substantial escape of fluid under pressure. As will also be seen, the diameters of passage Aland actuator or stem 3! are such that with the valve in unseated position, an adequate spaceis present for the flow of gas under pressure. I

Transverse passage 28 is also provided with a valve seat with which a valve 34 is cooperable; it being noted that one end of'this passage extends throughthe exteriorof the body Ill and is left unobstructed so that gas may vent through the same. The spring-pressed valve is also provided with a stem or actuator 35. This .ele-. ment preferably passes through a the bore of a packing and sealing assembly generally indicated at 36. Its outerend may conveniently terminate in a slotted portion 31. Accordingly, it is obvious that an inward pressure on the stem 3| will cause a shifting of the valve 39 to unseated posi-; tion whileanoutward pull on the actuator 35 will unseat valve 34.

To secure such shifting, the body H] or' an associated part may carry. a pivotallymounted handle 38. This handle is. urged in an outward direction by, for example, a spring 39. A flattened or contact portion 40 of the handle may be disposed in line with the outer end of the actuating stem 3!. A pin 4| carried by handl 38 may ride within the slotted portion 31 of actuator'35;

It follows that when handle 38 is swung inwardly against the resistance offered by spring 39, valve 34 will be shifted to closed position incidentto action of the spring cooperating therewith. As.

the handle shifts to its limit of movement, pin

4| will engage the end of slot 31 to exert a pull on stem 35. The value of spring 39 being in excess of the value of the spring cooperating with valve 34, it follows that the latter spring will be compressed and valve 34 will move to unseated position. As willalso be apparent from a con- :-sideration of this structure, gas under pressure willnorma'lly tend to seatva1ves-30 and 34. This action in itself may-in certain instances-make However, or-

andthe consequent avoidance of wastage of the source.

Now considering the structure as especially shown in Figs. 1 to 5, it will be noted that the plunger 25 may carry abutments 42. These may actually be inthenature of pins or rods extending through the. plunger 25 and arranged in the fQ m of a spiral series. \Vhile in the embodiment under consideration only five pairs of these abutments have been illustrated, it is to be understood that a greater or lesser number might beemployed. Rotatably mounted and concentrically disposed with respect to plunger 25, at a point below the abutments 42. is a control means in theform of, a ring-shaped member 43. The latter may be formed with a series of indentations 44 in its exterior face andcorresponding to the number of abutments 42 employed. A spring-pressed detent member 45 may cooperate with these indentations. Expansible rings 46 may beemployed to extend into grooves formed in the-adjacent facesofring 43 and the channel of body portions l5 and 50 which receive the same. As especially shown in Fig. 4, the outer face of ring member 43 may be exposed upon and xten pey n a slot formed in the wall of body It. Thisslot may. extend throughout substantially 'Asin Fig. 2, screws or pins 4'! may be carried,lbythe ring at this point and ride within. the grooves formed in the'bo'dy of the unit l5'and its lower portionillv and which grooves also acc' ornm'o'dat e the expans'ible rings 46.

fIhe ring 43,'as shown in Fig. 4,'may carry inwardly extending projections or abutments 48. These are conveniently opposed to each other and their upper surfaces are capable of cooperating with the outer en'dsof a'pair of abutments 42 (Fig. '2) whi'c'hlie in the same plane. Finally, with resp'ect to thisportion of, the apparatus, it will benoted as inFig. l, thata scale indicated at 49 may appear upon ,the exterior face of body I5. This. scale mayregister with a suitable graduation upon the exterior face of ring 43. Having in. mindthat the embodiment herewith described includes five pairs of abutments, the graduations of the scale 49 may also include five divisions. As will be apparent according to the abutments 42 aligned with the abutments 48, the pistonand its associated structures may have a greater or lesser stroke range.

Conveniently, the lower end portion 50 of the unit will provide a medicament-receiving chamber or space. According to a preferred concept of, .the invention,.thdmedicament will be contained within an ampulej This ampule may take one of numerous difierent forms. .As illustrated the lower portion of .t he unit indicated by the end .mountedby a-cap 55. This cap is connected by screw ..threads, with corresponding threads formed on .the outerrloweriend of portion 50.

The boreo'f the cannula'continues in the form of.

apassage 56'awhich has a restricted outerend such thataiminute cross sectional area is presented. .As apparent, this passage may actually be formed by. the bore ofth cannula 54. Adjacent its outer or discharge end, cap 55 may be. formed with asealing flange or projection 51. The space betweenthe inner face of the cap and the outer end of the plunger 25, will be just suffici'ent to permit of theiinsertion of a'medicamentcontainin ampuleor. cartridge into .the chamber of portion50. Thereupon, 'cap 55 may be reapplied. In such 'reapplication, it is; apparent that the upper facezof stopper: 52 orequivalent sealing member will moveintoengagement with the outer end of plunger 25 while the cannula 54 will pierce stopper Y53 and be immersed within the body -'of the medicament. With such immersion and tightening of the parts, it is apparent that any air within bore 56 will be discharged by that bore bein filled with liquid medicament.

With a flask I! in positionas aforedescribed, it will be understood that the, apparatus ,is ready for use. Assuming that a physician desires for example to inject one cubic centimeter of medicament, the sealing portion 5,1'or other outer end surface of the cap or itseq uivalent' is brought into contact with the skinof the patient at a point overlying that atwhich the injection is to be made. Prior to such application of the device, the ring 43 is turned so that the abutm'ents or projections 58 of the same are inline with the lower or. outermost pair ofv projections 42xon plunger 25. In such turning, norotation'of the plunger will occur because the latter may be formed with a groove 58 which is engaged by an inwardly extending projection 59 conveniently forming a part of the endfportion 5D. With the valve mechanism operating, it is apparent that gas under pressure is admitted into cylinder 23 resulting in a projection of piston 24. Such projection will cause the lower end of plunger 25 to-bear against the stopper or piston portion 52 andto shift the latter. With such shifting, the medicament within body 5| will be expressed through the bore of cannula 54. This discharge will. obviously occur under high velocity and pressure. With the discharge end of bore 56 having sufficiently fine cross section, not alone will-the velocity of now be increased but also the stre'amof medicamentwill have such a minute transverse area that it will penetrate the epidermis without substantial pain to the patient or injury to the skin.

7 Considering the operation of the valve mechanism, especially shown in Fi'gs.'11 and 12, it will be understood that as afore brought out a shifting of the handle 38 seats the valve 34 and unseats the valve 30. Accordingly, the gas may flow from the bore of cannula I 9 through passages 2|, 21,29, 28 and 22 into the cylinder 23. This will produce the desired piston projection. With the release of handle 38,'valve 30 will seat to seal against discharge of further gas. Accordingly, the gas under pressure within flask I! or its equivalent will not accidentally escape and a single flask may be employed fora number of successive injections without it being necessary to; renew the flasln Therelease of the handle 38 allows valve 3 5. to. move to unseated position. With such movement, gas under pressure within cylinder 23 may flow backwardly through passage 22 and into transverse passage 28 to be vented to. the atmosphere through the unobstructed end of the latter. It is generally preferred .to relieve the pressure within thecylinde'r after each injection. By such relief, the operator may without difficulty adjust the parts of the apparatus to permit of a further injection; As will be appreciated, the valve mechanism has been somewhat schematically illustrated in order that the operation of the same may be clearly understood. In actual practice it is preferred that needlevalves be employed at 3B and 34. These should cooperate with line-seals in order to assure a proper seating of theparts, By such constructions, the valves may be shifted to seated and unseated positions with minimum eifort, the diameter of the valves having been somewhat exaggerated in the figures in question. Also, the actuating mechanism maybe'redesigned so that the valves may beshifted to seated and unseated positions by a structure of-simple design.

Ordinarily, a successive injection may again involve only the discharge of one cubiccentimeter of medicament through the epidermis into the underlying tissues. In that event, the indicating mark upon ring d3 will'be-shifted'to align with the second graduation or scale 49-; This will bring the abutments' or projections 48 of thering into registry with-the second pair of abutments or projections '42 of the plunger'25. Thereupon, by repeating the 'aforedescribed"sequence of operation, the plunger may be again projected to inject the desired quantity of medicament. Further injection will be interrupted when the pair of projections d2 come into contact with the projections or abutments '48. I. l

-If it is desired to inject two, three or more cubic centimeters. in a single operation, then the indicating-mark on ring 43 may be shifted to align with the proper graduation of scale-49. Withsuch'rotation of the ring, the pair of projections or abutments 48 will be aligned with v that pair of projections 42 on the plunger 25 which are spaced from the projections 48 a dis- 1 tance corresponding to the value of the injection to be given. Thereupon, by operating the valve mechanism, the injection may be completed. As is apparent with the pressure within the cylinder relieved as afore brought out, the ring may read ily be shifted Without it being necessary to even come undue frictional contact between the outer surfaces of a pair of projections-42 and the upper or inner surfaces of the projections 48. -More important, with such relief or venting of pressure,

adjacent ends of these parts are screw threaded and connected by a threaded collar 62. As especia1ly.;shown in Fig. 6, this collar may be conveniently slotted through 180 as indicated at Si/Mounted between the adjacent end edges of parts. 60 and 6! is a ring 64. The latter mounts opposed abutments or stop .portions 65. These are capable of being selectivelyengaged byone of the pairs of abutments or projections 42 carried by the plunger 25.

The face of the collar .52 adjacent the slot 63 is conveniently formed with a scale (not shown). This'scale maylregister with a projection forming apart of actuator 66 secured to ring 64. i The graduations may be substantially identical With thoseheretoforeindicated by the numeral 49. It is obvious that as ring 64 is adjusted to vari- .ous positions, itsabutments or stop portions 65 will register with one or another of the stop portions 42 carried by the plunger. Therefore,

upon the plunger being projected, engagement will occur. between those abutments 42 which are aligned with the abutments or stops E5. Consequently, the movements of the parts will be arrested and only a desired quantity of medicament will be expressed.

The same result as is achieved in the foregoing figures, is .also capableof accomplishment by the structureshown in Figs. '7 to 10 inclusive. In fact,in certain instances, that structure might be preferred to the ones heretofore described. In these latter views, the numeral 66 indicates the casing of the device to the upper end of whicha cap 61 may be applied; that cap conveniently enclosing and actuating a flask 68 containing a compressed gas. Body 66 is hollow and presents a cylinder chamber as heretofore described. Also, a suitable valve mechanism is interposed between the cylinder and the discharge end of the flask; Moreover, the lower end of body 66 provides a medicament-containing chamber which may have its lower end closed by a cap 69. This cap conveniently provides the orifice through which the fine stream ofmedicament is discharged at high velocities. As heretofore brought out, it is in many instances preferred that an ampule be disposed within this chamber and that the ampule l embody a construction such that pressure upon itsupper end results in. the expressing of the medicament. However, it is again to be understood that alternative structures of substantially different design may be employed.

, The inner face of body 66 is formed with a spirall extending groove 1!. This grooveconveniently extends throughout two complete convolutions.- Disposed within the bore of body 6B and below the cylinderof the same is a sleeve member 12. This member has a thread or spirally extending abutment 13 on its outer face and preferably, adjacent its upper end. As illustrated, this abutment extends throughout one complete convolution,- It is to be understood that while for purposes of strength itis preferred that the thread extend throughout an entire convolution, this need-not necessarily be so. In the event that thread 73 is shortened, the length of the thread or channel H might be diminished.

The lower portion of sleeve .12 'may present on its outerjface a series of indicating marks running for example from 1 to inclusive. These have been indicated by the reference numeral 14. Body 66 is formed with an opening or window within the zone ofLthe indicia 14. The numerals or other scale marks will be visible through this window; .Between the thread 13 and the surface presenting the indicia 14, the sleeve 12 is formed with an annular series of gear teeth 16. These preferably have a length slightly in excess of. the overall. stroke of the'plunger stem H. That.stroke-as will be understood is substantially. equal to the overall length of the chamber. containing ampule 10. Teeth 116 are engaged by the teeth of a gear 18 mounted for rotation by and extending beyond the outer face of body 66. Thus, it is apparent that as actuator I8 isrotated, sleeve 12 will be turned. This will result in an axial shifting of the. sleeve within body 66. The upper edge portion of this sleeve is of a diameter such that it provides a stop'for a shoulder or enlarged portion 19 formin apart. of plunger stem 11.

In order to prevent an accidental turning of the sleeve, a catch or restraining element may be employed. Thus, when an axial thrust is exerted upon the sleeve, the thread I3 will not ride within the groove lltresulting in an improper operation of the parts. Of course, if desired, the grooves H and thread 13 might be pitched to a lesser extent. This could be achieved by having the groove ll extend through more than one convolution; including for example two or three convolutions. Likewise, the ampule or medicament-receivin chamber could be made of larger diameter and less length so that the thread would not have to be pitched so steeply. Moreover, by having the teeth 16 of a type such that a wormwheel, rather than the gear 18, drives thesame, accidental rotation of the parts can be prevented.

In any event, with the sleeve 12 in position within the body 66, it will be assumed that the medicament-containing chamber is filled and the cap 69 is in position, if such a cap be employed. It will moreover be assumed that a flask has been punctured .as afore described and that therefore, motive pressure is available. Under these circumstances, sleeve '12 will be in a position where the numeral 1 is visible through window 15. This will betrue, conceding for example that only one cubic centimeter is to be injected. Under such circumstances, the upper edge of sleeve 1'2 .will be spaced from the adjacent edge of the plunger enlargement 19 a corresponding distance. If. with the apparatus properly disposed with respect to tissue which is to be injected the valve mechanism is now operated, then plunger 11 will be forced downwardly to express the desired amount of medicament. With the completion of the injection, enlargement 19 will engage the upper edge ofsleeve 12. These parts thus function as a stop to arrest movement of the plunger and expression of medicament at a pointwhere precisely the desired amount of the latter has been injected. If a larger dosage is to be injected, then sleeve 12 may be rotated so that its upper edge is spaced at greater distance from enlargement 19 or other arresting portion of the plunger. In this connection, it, is apparent that if the ampule or the medicament-containing chamber have for example a capacity of ten cubic centimeters, then not alone may individual and successive doses of any desired value be injected, but up to the entire capacity of the unit may be so injected in a single operation. All that will be necessary to effect this result will be for the physician or other operator to rotate the sleeve and axially move it to the desired'extent. In this connection, it will be undersood that any desired alternative mechanism might be employed for efiecting such rotation.

Thus, among others, the several objects of the invention as afore described are achieved. Obviously numerous changes in construction and rearrangement of the parts might be resortedto without departing from the spirit of the invention as defined by the claims. v

' What I [claim is: a

"1.'A device for the hypodermic injection of liquid medicament at skin-penetrating velocities without the use of a piercing needle, said device comprising a body formed with a medicamentreceiving chamber, a plunger movable with respect to said'body and acting upon the medicament within said chamber to, expel the same; the range of movement of said plunger being such that substantially all of the medicament within said chamber may be expelled in a single plunger comprising a body formedwith a .medicamentreceiving chamber, a plunger movable with respect tosaid body andacting upon the medicament within said chamber to expel the same; the range of movement :of said. plunger being such that substantially all of themedicament within said chamber may be expelled in a single plunger movement, a sleeve rotatably mounted with re: spect to said body and having-threaded-connec: tion therewith, said sleeve providing a stop to arrest plunger movement at points short of the limit of its range. of movement and means yfOI rotating said sleeve with respect to said body.

3. A device for the hypodermicinjectionof liquid medicament at skin-penetrating velocities without the use of a piercing needle, said device comprising a body formed with a medicamentreceiving chamber, -a plunger movable with respect to said body and acting upon the medicament within said chamber to expel the same; the range of movement of said plunger being such that substantially all of the medicament within said chamber may be expelled in a single plunger movement, a sleeve rotatably mounted with respect to said body and having threaded connection therewith, said sleeve providing a stop to arrest plunger movement at points short of the limit of; its range of movement, means for rotatingsaid sleeve with respect to said body and means for indicating the position to which said sleeve has been shifted.

4. A device for the hypodermic injection of liquid medicament at skin-penetrating velocities without the use of a piercing needle, said device comprising a body formed with a medicamentreceiving chamber, a plunger movablewith'respect to said body and acting upon the medicae ment within said chamber to expel the same; the range of movement of said plunger being such that substantially all of the medicament within said chamber may be expelled in'a single plunger movement, a sleeve rotatably mounted with respect to said body and having threaded connection therewith, said sleeve providing a stop to arrest plunger movement at points short of the limit of its range of movement, means for rotating said sleeve with respect to said body, a scale disposed upon the face of said sleeve and said body being formed with an opening through which the elements of said scale are visible.

, 5. A pressure-creating device for injecting medicament at velocities such that they will penetrate the skin without the use of a piercing needle, said device including a body formed with a medicament chamber having an outlet of reduced cross section, powermeans which upon full projection into said chamber will displace substantially all medicament therefrom, means mounted for rotation within said body and cooperative withsaid power means forarresting the projectionof the latter at a point short of its being fully projected, control means rotatably mounted by and extending beyond said body and means for connecting said control means with said arresting means for causing the latter to limit the projection of the power means at pre-determined points.

I 6. A pressure-creating device for injecting medicament at velocities such that they will penetrate the skin without the use of a piercing needle, said device including a body formed with a medicament chamber having an outlet of reduced cross section, power means which upon full projection into said chamber will displace substantially all medicament therefrom, means providing movement-limiting surfaces projecting from and shifta'ble with said power means, means mounted for movement within said body and extending into the path of travel of said surfaces to arrest the projection of said power means at a point short of its being fully projected and movable control means extending exteriorly of said body and operatively connected tosaid arresting means for shifting the latter.

' 7. A pressure-creating device for injecting medicament at velocities such that they will penetrate the skin without the use'of a piercing needle, said device including a body formed with a cylinder adjacent one end and a medicament chamber at the opposite end, said chamber having an outlet of reduced cross section, a piston shiftable within said cylinder in response to the introduction of fluid under pressure into the same, a stem connected to move with said piston and fully projectable into said chamber to displace substantially all medicament therefrom, control means, rotatable within said body and encircling said stem-and said control means providingsurfaces extending into the pathrof travel of parts associated withflsaid stem for arresting movement of the latter at a point short of its fully projected position.

8. A pressure-creating device for injecting medicament at velocities such that they will penetrate the skin without the use of a piercing needle, said device including a body formed with a cylinder adjacent one end and a medicament chamber at the opposit end, said chamber having'an outlet of reduced cross section, a piston shiftable within said cylinder in response to the introduction of fluid under pressure into the same, a stem connected to move with said piston and fully projectabie into said chamber to displace sub-' stantially all medicament therefrom, control means rotatable within said body and encircling said stem, said control means providing surfaces extending into the path of travel of parts associated with said stem for arresting movement of the latter at a point short of its fully projected position, and means mounted by and extending exteriorly of said body to shift said control means.

9. A pressure-creating device for injecting medicament at velocities such that they will penetrate the skin without the use of a piercin needle, said device including a body formed with a cylinder adjacent one end and a medicament chamber at the opposite end, said chamber having an outlet of reduced cross section, a piston shiftable within said cylinder in response to the introduction of fluid under pressure into the same, a stem connected to move with said piston and fully projectable into said chamber to displace substantially all medicament therefrom, control means rotatable within said body and encircling said stem, said control means providing surfaces extending into the path of travel of parts associated with said stem for arresting movement of the latter at a point short of its fully projected position, and means visible exteriorly of said body for indicating the position of said control means and accordingly th point at which the movement of said stem will be arrested.

10. An injection device for medicament comprising a body formed with a cylinder to receive fluid under pressure, a piston movable within said cylinder, said body being formed with amedicament-receiving chamber from which medicament is to be ejected, a plunger extending between said piston and chamber and acting in response to movement of the former to eject medicament from the latter, a sleeve rotatable within said body and presenting surfaces acting to arrest the movement of said piston, a spirally extending cooperating rib and groove structure forming a part of said body and sleeve whereby upon relative rotations being eifected between the sleeve and body the sleeve and its arresting surfaces will be shifted axially of the body and means extending beyond the outer face of the body for effecting such rotation.

11. A pressure-creating device for injecting medicament at velocities such that they will penetrate the skin without the use of a piercing needle, said device including a body formed with a medicament chamber having an outlet of reduced cross section, power means which upon full projection into said chamber will displace substantially all medicament therefrom, a series of abutments extending from said power means and laterally displaced with respect to each other and stop means movably carried by said body and selectively engageabl by one of said abutments to arrest movement of said power means at a point short of its full projection.

12. A pressure-creating device for injecting medicament at velocities such that they will penetrate the skin without the use of a piercing needle, said device including a body formed with a medicament chamber having an outlet of reduced cross section, power means which upon full projectioninto said chamber will displace substantially all medicament therefrom, a series of abutments extending from said power means and laterally displaced with respect to each other, a further abutment and means movably mounted by said body and carrying said further abutment to shift the latter whereby said abutment may be selectively contacted by one of said series of abutments to arrest movements of the power means.

13. A pressure-creating device for injecting medicament at velocities such that they will penetrate the skin without the use of a piercing needle, said device including a body formed with a medicament chamber having an outlet of reduced cross section, power means which upon full projection into said chamber will displace substantially all medicament therefrom, a series of abutments extending from said power means and laterally displaced .with respect to each other, a further abutment, means movably mounted by saidvbody and carrying said further abutment to shift the latter whereby said abutment may be selectively contacted by one of said series of abutments to arrest movements of the power means and means for confinin such latter movements toa substantially axial path.

14. A pressure-creating device for injecting medicament at velocities such that they will penetrate the skin without th use of a piercing needle, said device including a body formed with a medicament chamber having an outlet of reduced cross section, power means which upon full projection into said chamber Will displace substantially all medicament therefrom, a spirally arranged series of abutments extending from said power means, a ring-shaped member disposed in line with a slot extending circumferentially of said body, an inwardly extending abutment mounted by said member and said member being rotatable with respect to said body to shift said latter abutment into the path of travel of one of the first-named abutments.

JOHN H. SMOOT.

REFERENCES CITED 7 The following references are of record in the file of this patent: I

UNITED STATES PATENTS Number Name Date 1,015,276 Rowse Jan. 16, 1912 2,316,095 Mead, Jr. Apr. 6, 1943 r 2,322,244 Lockhart June 22, 1943 2,322,245 Lockhart June22, 1943 2,380,534 Lockhart July 31, 1945 2,409,656 Austin Oct. 22, 1946 2,457,859 Austin Jan. 14, 1949 

